02 Proton and Ion Accelerators and Applications
2E Superconducting Linacs
Paper Title Page
SUPB018 Studies of Parasitic Cavity Modes for Proposed ESS Linac Lattices 47
 
  • R. Ainsworth
    Royal Holloway, University of London, Surrey, United Kingdom
  • S. Molloy
    ESS, Lund, Sweden
 
  The European Spallation Source (ESS) planned for construction in Lund, Sweden, will be the worlds most intense source of pulsed neutrons. The neutrons will be generated by the collision of a 2.5 GeV proton beam with a heavy-metal target. The superconducting section of the proton linac is split into three different types of cavities, and a question for the lattice designers is at which points in the beamline these splits should occur. This note studies various proposed designs for the ESS lattice from the point of view of the effect on the beam dynamics of the parasitic cavity modes lying close in frequency to the fundamental accelerating mode. Each linac design is characterised by the initial kinetic energy of the beam, as well as by the velocity of the beam at each of the points at which the cavity style changes. The scale of the phase-space disruption of the proton pulse is discussed, and some general conclusions for lattice designers are stated.  
 
SUPB019 The Multipacting Simulation for the New-Shaped QWR using TRACK3P 50
 
  • C. Zhang, S. He, Y. He, S.C. Huang, Y.L. Huang, T.C. Jiang, R.X. Wang, M.X. Xu, Y.Z. Yang, W.M. Yue, S.H. Zhang, S.X. Zhang, H.W. Zhao
    IMP, Lanzhou, People's Republic of China
 
  In order to improve the electro-magnetic performance of the quarter wave resonator, a new-shaped cavity with an elliptical cylinder outer conductor has been proposed. This novel cavity design can provide much lower peak surface magnetic field and much higher Ra/Q0 and G. The Multipacting simulation has been done for this new QWR cavity using ACE3P/TRACK3P code, in this paper the simulation results will be presented and analyzed.  
 
SUPB020 Structural Analysis of the New-Shaped QWR for HIAF in IMP 53
 
  • C. Zhang, S. He, Y. He, S.C. Huang, Y.L. Huang, T.C. Jiang, R.X. Wang, Y.Z. Yang, W.M. Yue, S.H. Zhang, S.X. Zhang, H.W. Zhao
    IMP, Lanzhou, People's Republic of China
  • M.H. Xu
    IHEP, Beijing, People's Republic of China
 
  Since the QWR cavity is very successful for the operation with frequency of 48 to 160 MHz and beta value of 0.001 to 0.2, a new-shaped QWR is being designed for the low energy superconducting section of HIAF in the Institute of Modern Physics. The cavity will work at 81.25 MHz and \beta of 0.085,with a elliptical cylinder outer conductor to better its electro-magnetic performance and keep limited accelerating space. Structural design is an important aspect of the overall cavity implementation, and in order to minimize the frequency shift of the cavity due to the helium bath pressure fluctuations, the Lorentz force and microphonic excitation, stiffening elements have to be applied. In this paper, structural analyses of the new-shaped QWR are presented and stiffening methods are explored.  
 
SUPB022 First Measurements on the 325 MHz Superconducting CH Cavity 56
 
  • M. Busch, F.D. Dziuba, H. Podlech, U. Ratzinger
    IAP, Frankfurt am Main, Germany
  • M. Amberg
    HIM, Mainz, Germany
  • W.A. Barth, S. Mickat
    GSI, Darmstadt, Germany
  • M. Pekeler
    RI Research Instruments GmbH, Bergisch Gladbach, Germany
 
  Funding: Work supported by HIM, GSI, BMBF Contr. No. 06FY161I
At the Institute for Applied Physics (IAP), Frankfurt University, a superconducting 325 MHz CH-Cavity has been designed and built. This 7-cell cavity has a geometrical \beta of 0.16 corresponding to a beam energy of 11.4 AMeV. The design gradient is 5 MV/m. Novel features of this resonator are a compact design, low peak fields, easy surface processing and power coupling. Furthermore a new tuning system based on bellow tuners inside the resonator will control the frequency during operation. After successful rf tests in Frankfurt the cavity will be tested with a 10 mA, 11.4 AMeV beam delivered by the GSI UNILAC. In this paper first measurements and corresponding simulations will be presented.
 
 
SUPB023 Status of the Superconducting CW Demonstrator for GSI 59
 
  • F.D. Dziuba, M. Amberg, M. Busch, H. Podlech, U. Ratzinger
    IAP, Frankfurt am Main, Germany
  • K. Aulenbacher
    IKP, Mainz, Germany
  • W.A. Barth, S. Mickat
    GSI, Darmstadt, Germany
 
  Funding: Helmholtz Institut Mainz (HIM), GSI, BMBF Contr. No. 06FY7102
Since the existing UNILAC at GSI will be used as an injector for the FAIR facility a new superconducting (sc) continous wave (cw) LINAC is highly requested by a broad community of future users to fulfil the requirements of nuclear chemistry, especially in the research field of Super Heavy Elements (SHE). This LINAC is under design in collaboration with the Institute for Applied Physics (IAP) of Frankfurt University, GSI and the Helmholtz Institut Mainz (HIM). It will consist of 9 sc Crossbar-H-mode (CH) cavities operated at 217 MHz which provide an energy up to 7.3 AMeV. Currently, a prototype of the cw LINAC is under development. This demonstrator comprises the first sc CH cavity of the LINAC embedded between two sc solenoids mounted in a horizontal cryomodule. One important milestone of the project will be a full performance test of the demonstrator by injecting and accelerating a beam from the GSI High Charge State Injector (HLI) in 2014. The status of the demonstrator is presented.
 
 
TU1A03 Chinese ADS Project and Proton Accelerator Development 412
 
  • Y.L. Chi, S. Fu, W.M. Pan, P. Sha
    IHEP, Beijing, People's Republic of China
  • Q.Z. Xing
    TUB, Beijing, People's Republic of China
 
  Interest in the feasibility of ADS has increased dramatically in the last decade. This talk will briefly introduce the technologies presently available for ADS applications and provide a review of the ongoing R&D and construction activities in China, with particular emphasis on the challenges presented by the development of a high intensity, SRF CW proton Linac.  
slides icon Slides TU1A03 [3.803 MB]  
 
TUPLB07 Reduced-beta Cavities for High-intensity Compact Accelerators 458
 
  • Z.A. Conway, S.M. Gerbick, M. Kedzie, M.P. Kelly, J.W. Morgan, R.C. Murphy, P.N. Ostroumov, T. Reid
    ANL, Argonne, USA
 
  Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under contract number DE-AC02-06CH11357 and WFO 8R268.
This paper reports on the development and testing of a superconducting quarter-wave and a superconducting half-wave resonator. The quarter-wave resonator is designed for β = 0.077 ions, operates at 72 MHz and can provide more than 7.4 MV of accelerating voltage at the design beta, with peak surface fields of 164 mT and 117 MV/m. Operation was limited to this level not by RF surface defects but by our available RF power and administrative limits on x-ray production. A similar goal is being pursued in the development of a half-wave resonator designed for β = 0.29 ions and operated at 325 MHz.
 
 
TUPLB08 R&D Towards CW Ion Linacs at ANL 461
 
  • P.N. Ostroumov, A. Barcikowski, Z.A. Conway, S.M. Gerbick, M. Kedzie, M.P. Kelly, S.V. Kutsaev, J.W. Morgan, R.C. Murphy, B. Mustapha, D.R. Paskvan, T. Reid, D.L. Schrage, S.I. Sharamentov, K.W. Shepard, G.P. Zinkann
    ANL, Argonne, USA
 
  Funding: This work was supported by the U.S. Department of Energy, Office of High Energy Physics and Nuclear Physics, under Contract DE-AC02-76CH03000, DE-AC02-06CH11357 and ANL WFO 85Y47.
The accelerator development group in ANL’s Physics Division has engaged in substantial R&D related to CW proton and ion accelerators. Particularly, a 4 meter long 60.625 MHz CW RFQ has been developed, built and is being commissioned with beam. Development and fabrication of a cryomodule with seven 72.75 MHz quarter-wave cavities is complete and it is being assembled. Off-line testing of several QWRs has demonstrated outstanding performance in terms of both accelerating voltage and surface resistance. Both the RFQ and cryomodule were developed and built to upgrade ATLAS to higher efficiency and beam intensities. Another cryomodule with eight 162.5 MHz SC HWRs and eight SC solenoids is being developed and built for Project X at FNAL. We are also developing both an RFQ and cryomodules (housing 176 MHz HWRs) for proton & deuteron acceleration at SNRC (Soreq, Israel). In this paper we discuss ANL-developed technologies for normal-conducting and SC accelerating structures for medium- and high-power CW accelerators, including the projects mentioned above and other developments for applications such as transmutation of spent reactor fuel.
 
slides icon Slides TUPLB08 [1.414 MB]  
 
TUPB046 R&D Towards CW Ion Linacs at ANL 579
 
  • P.N. Ostroumov, A. Barcikowski, Z.A. Conway, S.M. Gerbick, M. Kedzie, M.P. Kelly, S.V. Kutsaev, J.W. Morgan, R.C. Murphy, B. Mustapha, D.R. Paskvan, T. Reid, D.L. Schrage, S.I. Sharamentov, K.W. Shepard, G.P. Zinkann
    ANL, Argonne, USA
 
  Funding: This work was supported by the U.S. Department of Energy, Office of High Energy Physics and Nuclear Physics, under Contract DE-AC02-76CH03000, DE-AC02-06CH11357 and ANL WFO 85Y47.
The accelerator development group in ANL’s Physics Division has engaged in substantial R&D related to CW proton and ion accelerators. Particularly, a 4 meter long 60.625 MHz CW RFQ has been developed, built and is being commissioned with beam. Development and fabrication of a cryomodule with seven 72.75 MHz quarter-wave cavities is complete and it is being assembled. Off-line testing of several QWRs has demonstrated outstanding performance in terms of both accelerating voltage and surface resistance. Both the RFQ and cryomodule were developed and built to upgrade ATLAS to higher efficiency and beam intensities. Another cryomodule with eight 162.5 MHz SC HWRs and eight SC solenoids is being developed and built for Project X at FNAL. We are also developing both an RFQ and cryomodules (housing 176 MHz HWRs) for proton & deuteron acceleration at SNRC (Soreq, Israel). In this paper we discuss ANL-developed technologies for normal-conducting and SC accelerating structures for medium- and high-power CW accelerators, including the projects mentioned above and other developments for applications such as transmutation of spent reactor fuel.
 
 
TUPB047 Status of the Superconducting RF Activities for the HIE ISOLDE Project 582
 
  • W. Venturini Delsolaro, L. Alberty Vieira, S. Calatroni, O. Capatina, A. D'Elia, B. Delaup, M.A. Fraser, N.M. Jecklin, Y. Kadi, P. Maesen, I. Mondino, E. Montesinos, M. Therasse, D. Valuch
    CERN, Geneva, Switzerland
 
  The planned upgrade of the REX ISOLDE facility at CERN will boost the energy of the machine from 3 MeV/u up to 10 MeV/u with beams of mass-to-charge ratio 2.5 < A/q < 4. For this purpose, a new superconducting post accelerator based on independently phased 101.28 MHz Quarter Wave Resonators (QWR) will replace part of the normal conducting Linac. The QWRs make use of the Niobium sputtering on Copper technology which was successfully applied to LEP2, LHC and to the energy upgrade of the ALPI Linac at INFN-LNL. The status of advancement of the project will be detailed, limited to the SRF activities.  
 
TUPB048 Discussion of the Optimisation of a Linac Lattice to Minimise Disruption by a Class of Parasitic Modes 585
 
  • S. Molloy
    ESS, Lund, Sweden
  • R. Ainsworth
    Royal Holloway, University of London, Surrey, United Kingdom
 
  It is well known that each resonant mode in the RF spectrum of multi-cell accelerating cavities will split into a passband containing a number of modes, and that the coupling of these modes to the beam is dependent on the velocity of the accelerated particles. If these modes are found to degrade the quality of the beam, it is possible to take various measures to damp them, and thus keep their effect below some critical threshold. In the case of the parasitic modes within the same passband as the fundamental accelerating mode, their frequency is typically too close to that of the fundamental to allow their power to be safely extracted, and so cavity designers must rely on the natural damping of the cavity itself. This note contains a theoretical discussion of the coupling of the beam to these passband modes for a large class of accelerating cavities, and provides a mathematical model for use during the design and optimisation of linacs.  
 
TUPB049 Superconducting Low Beta Niobium Resonator for Heavy Ions 588
 
  • P.N. Prakash, K.K. Mistri, A. Roy, J. Sacharias, S.S. Sonti
    IUAC, New Delhi, India
 
  For the high current injector at Inter-University Accelerator Centre, a new superconducting niobium resonator optimized for β = 0.05 operating at 97 MHz, has been designed and fabricated. This resonator has the highest frequency in its class among the superconducting structures designed for such low velocity particles. The resonator has been carefully modeled using Microwave Studio code to minimize the peak magnetic field in order to achieve high accelerating gradients in it. Even though the resonance frequency is high, the physical dimensions of the resonator are large enough to allow processing of its superconducting surface effectively. The mechanical design of the resonator has been modeled using ANSYS multiphysics to increase the frequency of the lowest mechanical eigenmode of the central co-axial line, and also reduce liquid helium induced pressure fluctuations in the resonator. Bead pull measurements have been performed on the niobium resonator and they match with the design values very well. Cold tests at 4.2 K will be performed in the next few weeks. This paper will briefly present the design of the low beta resonator and details of the results from the cold tests.  
 
TUPB052 Studies of Parasitic Cavity Modes for Proposed ESS Linac Lattices 591
 
  • R. Ainsworth
    Royal Holloway, University of London, Surrey, United Kingdom
  • S. Molloy
    ESS, Lund, Sweden
 
  The European Spallation Source (ESS) planned for construction in Lund, Sweden, will be the worlds most intense source of pulsed neutrons. The neutrons will be generated by the collision of a 2.5 GeV proton beam with a heavy-metal target. The superconducting section of the proton linac is split into three different types of cavities, and a question for the lattice designers is at which points in the beamline these splits should occur. This note studies various proposed designs for the ESS lattice from the point of view of the effect on the beam dynamics of the parasitic cavity modes lying close in frequency to the fundamental accelerating mode. Each linac design is characterised by the initial kinetic energy of the beam, as well as by the velocity of the beam at each of the points at which the cavity style changes. The scale of the phase-space disruption of the proton pulse is discussed, and some general conclusions for lattice designers are stated.  
 
TUPB053 Main Coupler Design for Project X 594
 
  • S. Kazakov, S. Cheban, T.N. Khabiboulline, M. Kramp, Y. Orlov, V. Poloubotko, O. Pronitchev, V.P. Yakovlev
    Fermilab, Batavia, USA
  • M.S. Champion
    ORNL, Oak Ridge, Tennessee, USA
 
  A multi-megawatt proton/H source, Project X, is under development at Fermi National Accelerator Laboratory. Main element of it is a 3 GeV superconducting proton linac which includes 5 families of superconducting cavities of three frequencies: 162.5, 325 and 650 MHz. Scope of this paper is the development of power couplers for 325 and 650 MHz at FNAL. Upgraded version of the accelerator will require two types of couplers, which reliably can operate at CW power level ~25 kW at 325 MHz and ~100 kW at 650 MHz respectively. In this paper we are describing the current design of these devices.  
 
TUPB054 Coherent Effects of High Current Beam in Project-X Linac 597
 
  • A.I. Sukhanov, I.V. Gonin, T.N. Khabiboulline, A. Lunin, A. Saini, N. Solyak, A. Vostrikov, V.P. Yakovlev
    Fermilab, Batavia, USA
 
  Resonance excitation of longitudinal high order modes in superconducting RF structures of Project X CW linac is studied. We analyze regimes of operation of the linac with high beam current, which can be used to provide an intense muon source for the future Neutrino Factory or Muon Collider, and also important for the Accelerator-Driven Subcritical (ADS) systems. We calculate power loss and associated heat load to the cryogenic system. Longitudinal emittance growth is estimated. We consider an alternative design of the elliptical cavity for the high energy part of linac, which is more suitable for high current operation.  
 
TUPB055 R&D of IMP Superconducting HWR for China ADS 600
 
  • W.M. Yue, X.L. Guo, S. He, Y. He, R.X. Wang, P.R. Xiong, M.X. Xu, B. Zhang, C. Zhang, S.H. Zhang, S.X. Zhang, H.W. Zhao
    IMP, Lanzhou, People's Republic of China
 
  The R&D program of IMP superconducting HWR is based on the China ADS, The aim is to build and test a HWR prototype on December 2012. We have designed a 162.5 MHz β=0.09 half-wave resonator (HWR), and a copper HWR has been fabricated in January 2012. The fabrication of a Nb HWR will be completed by September 2012, and the fabrication of a slow tuner and a high power coupler for this HWR will be completed then. In this poster, we present the HWR electromagnetic design, mechanical design, fabrication arts, copper HWR RF test result, the design of the slow tuner and the power coupler.  
 
TUPB056 The Multipacting Simulation for the New-shaped QWR using TRACK3P 603
 
  • C. Zhang, S. He, Y. He, S.C. Huang, Y.L. Huang, T.C. Jiang, R.X. Wang, M.X. Xu, Y.Z. Yang, W.M. Yue, S.H. Zhang, S.X. Zhang, H.W. Zhao
    IMP, Lanzhou, People's Republic of China
 
  In order to improve the electro-magnetic performance of the quarter wave resonator, a new-shaped cavity with an elliptical cylinder outer conductor has been proposed. This novel cavity design can provide much lower peak surface magnetic field and much higher Ra/Q0 and G. The Multipacting simulation has been done for this new QWR cavity using ACE3P/TRACK3P code, in this paper the simulation results will be presented and analyzed.  
 
TUPB057 Structural Analysis of the New-Shaped QWR for HIAF in IMP 606
 
  • C. Zhang, S. He, Y. He, S.C. Huang, Y.L. Huang, T.C. Jiang, R.X. Wang, M.X. Xu, Y.Z. Yang, W.M. Yue, S.H. Zhang, S.X. Zhang, H.W. Zhao
    IMP, Lanzhou, People's Republic of China
 
  Since the QWR cavity is very successful for the operation with frequency of 48 to 160 MHz and \beta value of 0.001 to 0.2, a new-shaped QWR is being designed for the low energy superconducting section of HIAF in the Institute of Modern Physics. The cavity will work at 81.25 MHz and \beta of 0.085,with a elliptical cylinder outer conductor to better its electro-magnetic performance and keep limited accelerating space. Structural design is an important aspect of the overall cavity implementation, and in order to minimize the frequency shift of the cavity due to the helium bath pressure fluctuations, the Lorentz force and microphonic excitation, stiffening elements have to be applied. In this paper, structural analyses of the new-shaped QWR are presented and stiffening methods are explored.  
 
TUPB058 An Analytical Cavity Model for Fast Linac-Beam Tuning 609
 
  • Z.Q. He, Z. Zheng
    TUB, Beijing, People's Republic of China
  • Z.Q. He, Z. Liu, J. Wei, Y. Zhang
    FRIB, East Lansing, Michigan, USA
 
  Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
Non-axisymmetric RF cavities can produce axially asymmetric acceleration fields. Conventional method using numerical 3-D field tracking to address this feature is time-consuming and thus not appropriate for on-line beam tuning applications. In this paper, we develop analytical treatment of non-axisymmetric RF cavities. Multipole models of cavities are derived using realistic 3-D field in both longitudinal and transverse dimensions. Then, beam dynamics formulism is established. Finally, special case of FRIB quarter-wave resonators are calculated by the model and benchmarked against 3-D field tracking to ensure the efficiency and accuracy of the model.
 
 
TUPB060 Multipacting Suppression Modeling for Half Wave Resonator and RF Coupler* 612
 
  • Z. Zheng, A. Facco, Z. Liu, J. Popielarski, K. Saito, J. Wei, Y. Xu, Y. Zhang
    FRIB, East Lansing, Michigan, USA
  • Z. Zheng
    TUB, Beijing, People's Republic of China
 
  Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
In prototype cryomodule test of Facility of Rare Isotope Beam (FRIB) β=0.53 half-wave-resonators (HWRs) severe multipacting barriers, prevented RF measurement at the full field specified. The multipacting could not be removed by several hours of RF conditioning. To better understand and to eliminate multipacting, physics models and CST simulations have been developed for both cavity and RF coupler. The simulations have good agreement with the multipacting discovered in coupler and cavity testing. Proposed cavity and coupler geometric optimizations are discussed in this paper.
 
 
TUPB061 ADRC Control for Beam Loading and Microphonics 615
 
  • Z. Zheng, Z. Liu, J. Wei, Y. Zhang, S. Zhao
    FRIB, East Lansing, Michigan, USA
  • Z. Zheng
    TUB, Beijing, People's Republic of China
 
  Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
Superconducting RF (SRF) cavities are subject to many disturbances such as beam loading and microphonics. Although we implemented Proportional Integral (PI) control and Active Disturbance Rejection Control (ADRC) in the Low Level RF (LLRF) system at FRIB to stabilize the RF field, the control loop gains are inadequate in the presence of beam loading and microphonics. An improved scheme is proposed and simulated with much higher gains are achieved. The feasibility to include piezo tuner in ADRC and PI circuit is also presented in this paper.
 
 
TUPB062 Longitudinal Dynamic Analysis for the Project X 3-8 GeV Pulsed Linac 618
 
  • G.I. Cancelo, B. Chase, Y.I. Eidelman, S. Nagaitsev, N. Solyak
    Fermilab, Batavia, USA
 
  The Pulsed Linac is a will require over 200 9-cell, 1300 MHz cavities packed in 26 ILC type cryomodules to accelerate 1 mA average beam current from 3GeV to 8 GeV. The architecture of the RF must optimize RF power, beam emittance, and energy gain amid a large number of requirement and constraints. The pulse length is a critical issue. Ideally, a 26 ms pulse would allow direct injection into the Fermilab’s Main Injector, bypassing the need of the Fermilab’s Recicler. High loaded quality factors (QL) are also desirable to minimize RF power. These requirements demand an accurate control of the cavity resonant frequency disturbed by Lorentz Force Detuning and microphonics. Also the LLRF control system must regulate the RF amplitude and phase within tight bounds amid a long list of dynamic disturbances. The present work describes the simulation efforts and measurements at Fermilab facilities.  
 
TUPB066 Reduced-beta Cavities for High-intensity Compact Accelerators 621
 
  • Z.A. Conway, S.M. Gerbick, M. Kedzie, M.P. Kelly, J.W. Morgan, R.C. Murphy, P.N. Ostroumov, T. Reid
    ANL, Argonne, USA
 
  Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under contract number DE-AC02-06CH11357 and WFO 8R268.
This paper reports on the development and testing of a superconducting quarter-wave and a superconducting half-wave resonator. The quarter-wave resonator is designed for β = 0.077 ions, operates at 72 MHz and can provide more than 7.4 MV of accelerating voltage at the design beta, with peak surface fields of 164 mT and 117 MV/m. Operation was limited to this level not by RF surface defects but by our available RF power and administrative limits on x-ray production. A similar goal is being pursued in the development of a half-wave resonator designed for β = 0.29 ions and operated at 325 MHz.
 
 
TUPB067 Development of a Superconducting Half-Wave Resonator for PXIE 624
 
  • Z.A. Conway, R.L. Fischer, S.M. Gerbick, M. Kedzie, M.P. Kelly, S.V. Kutsaev, B. Mustapha, P.N. Ostroumov, K.W. Shepard
    ANL, Argonne, USA
  • I.V. Gonin, A. Lunin, V.P. Yakovlev
    Fermilab, Batavia, USA
 
  Funding: This work was supported by the U.S. Department of Energy, Office of High Energy Physics and Nuclear Physics, under contract DE-AC02-76CH03000 and DE-AC02-06CH11357
An ambitious upgrade to the FNAL accelerator complex is progressing in the Project-X Injector Experiment (PXIE). The PXIE accelerator requires 8 superconducting half-wave resonators optimized for the acceleration of 1 mA β = 0.11 H ion beams. Here we present the status of the half-wave resonator development, focusing particularly on cavity design, with a brief update on prototype fabrication.
 
 
TUPB068 Cryomodule Designs for Superconducting Half-Wave Resonators 627
 
  • Z.A. Conway, G.L. Cherry, R.L. Fischer, S.M. Gerbick, M. Kedzie, M.P. Kelly, S.H. Kim, J.W. Morgan, P.N. Ostroumov, K.W. Shepard
    ANL, Argonne, USA
 
  Funding: This work was supported by the U.S. DOE, Office of Nuclear Physics, contract number DE-AC02-06CH11357, WFO 85Y47 supported by SNRC, and WFO 82308 supported by Fermi National Accelerator Laboratory.
In this paper we present advanced techniques for the construction of half-wave resonator cryomodules. Recent advances in superconducting low-beta cavity design and processing have yielded dramatically improved cavity performance which reduce accelerator cost and improve operational reliability. This improvement has led to the proposal and construction of half-wave resonators by ANL for the acceleration of 0.1 < \beta < 0.5 ions, e.g., the SARAF Phase-II project at SNRC (SOREQ, Israel) and Project-X at Fermilab. These cryomodules build and improve upon designs and techniques recently implemented in upgrades to ATLAS at ANL. Design issues include the ease of assembly/maintenance, resonator cleanliness, operating at 2 or 4 Kelvin, and ancillary system interfacing.
 
 
TUPB069 BEAMDULAC-SCL Code for Complex Approach of Beam Dynamic Investigation in SC LINAC 630
 
  • A.V. Samoshin
    MEPhI, Moscow, Russia
 
  Periodic sequences of independently phased accelerating cavities and focusing solenoids are used in MeV and GeV energy range linacs. The beam dynamic investigation is difficult for such superconducting linear accelerator. The matrix calculation was preferably used for primary choused of accelerating structure parameters. This method does not allows properly investigate the longitudinal motion. The smooth approximation can be used to investigate the nonlinear ion beam dynamics in such accelerating structure and to calculate longitudinal and transverse acceptances. The potential function and the equation of motion in the Hamilton form are devised by the smooth approximation. The advantages and disadvantages of each method will describe, the results of investigation will compare. The user friendly software BEAMDULAC-SCL for ion beam dynamic analysis was created. A numerical simulation of beam dynamics in the real field are carried out for the different variants of the accelerator structure based on previously analytically obtained results.  
 
TUPB070 Development of Proton Therapy at the SC Linac with BEAMDULAC-SCL Code 633
 
  • A.V. Samoshin, S.M. Polozov
    MEPhI, Moscow, Russia
 
  Proton cancer therapy complexes are conventionally developing based on synchrotrons and cyclotrons. High electrical power consumption and especial devices necessary to energy variation (as slow extraction systems and degraders) are the main problems of such complexes. At once SC linacs based on short independently phased quarter and half wave cavities have a serious progress at present. Linear accelerator consumes less power comparably with cyclic and the energy variation can be easily realized by means of RF field amplitude and phase variation in a number of cavities. The accelerator’s modular configuration which is now widely used in FRIBs * or SNSs can be applied for therapy linac also (see for example **). It is possible to choose the SC linac parameters and proton and ion beams stability study with help of the BEAMDULAC-SCL code. This software also allows providing of the structure optimization and the beam dynamics control.
* P.N. Ostroumov and et al., Proc. of PAC2001, p.4080.
** C.Ronsivalle et al. Proc. of IPAC 2011, p. 3580.
 
 
TUPB071 First Measurements on the 325 MHz Superconducting CH Cavity 636
 
  • M. Busch, F.D. Dziuba, H. Podlech, U. Ratzinger
    IAP, Frankfurt am Main, Germany
  • M. Amberg
    HIM, Mainz, Germany
  • W.A. Barth, S. Mickat
    GSI, Darmstadt, Germany
  • M. Pekeler
    RI Research Instruments GmbH, Bergisch Gladbach, Germany
 
  Funding: Work supported by GSI, BMBF Contr. No. 06FY7102, 06FY9089I
At the Institute for Applied Physics (IAP), Frankfurt University, a superconducting 325 MHz CH-Cavity has been designed and built. This 7-cell cavity has a geometrical \beta of 0.16 corresponding to a beam energy of 11.4 AMeV. The design gradient is 5 MV/m. Novel features of this resonator are a compact design, low peak fields, easy surface processing and power coupling. Furthermore a new tuning system based on bellow tuners inside the resonator will control the frequency during operation. After successful rf tests in Frankfurt the cavity will be tested with a 10 mA, 11.4 AMeV beam delivered by the GSI UNILAC. In this paper first measurements and corresponding simulations will be presented.
 
 
TUPB072 Status of the Superconducting CW Demonstrator for GSI 639
 
  • F.D. Dziuba, M. Amberg, M. Busch, H. Podlech, U. Ratzinger
    IAP, Frankfurt am Main, Germany
  • K. Aulenbacher
    IKP, Mainz, Germany
  • W.A. Barth, S. Mickat
    GSI, Darmstadt, Germany
 
  Funding: Helmholtz Institut Mainz (HIM), GSI, BMBF Contr. No. 06FY7102
Since the existing UNILAC at GSI will be used as an injector for the FAIR facility a new superconducting (sc) continous wave (cw) LINAC is highly requested by a broad community of future users to fulfil the requirements of nuclear chemistry, especially in the research field of Super Heavy Elements (SHE). This LINAC is under design in collaboration with the Institute for Applied Physics (IAP) of Frankfurt University, GSI and the Helmholtz Institut Mainz (HIM). It will consist of 9 sc Crossbar-H-mode (CH) cavities operated at 217 MHz which provide an energy up to 7.3 AMeV. Currently, a prototype of the cw LINAC is under development. This demonstrator comprises the first sc CH cavity of the LINAC embedded between two sc solenoids mounted in a horizontal cryomodule. One important milestone of the project will be a full performance test of the demonstrator by injecting and accelerating a beam from the GSI High Charge State Injector (HLI) in 2014. The status of the demonstrator is presented.
 
 
TUPB073 Design and Simulation of a Test Model for a Tri-Spoke Cavity at RIKEN 642
 
  • L. Lu
    RIKEN, Saitama, Japan
  • O. Kamigaito, N. Sakamoto, K. Suda, K. Yamada
    RIKEN Nishina Center, Wako, Japan
 
  A design for a tri-spoke-type superconducting cavity for uranium beams with β = 0.303 and a 219 MHz operational frequency is presented. And a test model designed and assembled by two end-wall flanges and one triparted part of the designed tri-spoke cavity, was expected to be built using the same fabrication technology that is supposed for Nb cavity manufacture. The designs and simulations of the tri-spoke cavity and the test model will be reported in this paper.  
 
TUPB074 Superconducting CW Heavy Ion Linac at GSI 645
 
  • W.A. Barth, V. Gettmann, S. Mickat
    GSI, Darmstadt, Germany
  • W.A. Barth, P. Gerhard
    HIM, Mainz, Germany
 
  Funding: Helmholtz Institute Mainz (HIM)
An upgrade program has to be realized in the next years, such that enhanced primary beam intensities at the experiment target are available. For this a new sc 28 GHz full performance ECR ion source is under development. Via a new low energy beam line an already installed new RFQ and an IH-DTL will provide for cw-heavy ion beams with high average beam intensity. It is planned to build a new cw-heavy ion-linac behind this high charge state injector. In preparation an R&D program is still ongoing: The first linac section comprising a sc CH-cavity embedded by two sc solenoids (financed by HIM) as a demonstrator will be tested with beam at the GSI High Charge Injector (HLI).The new linac should feed the GSI flagship experiments SHIP and TASCA, as well as material research, biophysics and plasma physics experiments in the MeV/u-area. The linac will be integrated in the GSI-UNILAC-environment; it is housed by the existing constructions. Different layout scenarios of a multipurpose high intensity heavy ion facility will be presented as well as the schedule for preparation and integration of the new cw-linac.
 
 
TUPB075 Beam Dynamics Design of China ADS Proton Linac 648
 
  • Z. Li, P. Cheng, H. Geng, Z. Guo, C. Meng, B. Sun, J.Y. Tang, F. Yan
    IHEP, Beijing, People's Republic of China
 
  Funding: Supported by China ADS Program(XDA03020000), National Natural Science Fundation of China (10875099) and IHEP Special Fundings(Y0515550U1)
It is widely accepted that the Accelerator Driven System (ADS) is one of the most promising technical approach to solve the problem of the nuclear wastes, a potential threaten to the sustainable development of the nuclear fission energy. An ADS study program is approved by Chinese Academy of Sciences at 2011, which aims to design and built an ADS demonstration facility with the capability of more than 1000 MW thermal power within the following 25 years. The 15 MW driver accelerator will be designed and constructed by the Institute of High Energy Physics(IHEP) and Institute of Modern Physics(IMP) of China Academy of Sciences. This linac is characterized by the 1.5 GeV energy, 10mA current and CW operation. It is composed by two parallel 10 MeV injectors and a main linac integrated with fault tolerance design. The superconducting acceleration structures are employed except the RFQ. In this paper the general considerations and the beam dynamics design of the driver accelerator will be presented.
 
 
TUPB104 Study of the Beam Dynamics in the RISP Driver Linac 705
 
  • H.J. Kim, J.G. Hwang, D. Jeon
    IBS, Daejeon, Republic of Korea
 
  Rare Isotope Science Project (RISP) has been proposed as a multi-purpose accelerator facility for providing beams of exotic rare isotopes of various energies. The RISP driver linac which is used to accelerate the beam, for an example, Uranium ions from 0.3 MeV/u to 200 MeV/u consists of superconducting RF cavities and warm quadrupole magnets for focusing heavy ion beams. Requirement of the linac design is especially high for acceleration of multiple charge beams. In this paper, we present the requirements of dynamic errors and correction schemes to minimize the beam centroid oscillation and preserve beam losses under control.  
 
TUPB107 Amplitude and Phase Control of the Accelerating Field in the ESS Spoke Cavity 708
 
  • V.A. Goryashko, R.J.M.Y. Ruber, R.A. Yogi, V.G. Ziemann
    Uppsala University, Uppsala, Sweden
 
  We report about numerical simulations of the accelerating field dynamics in the ESS spoke cavity in the presence of the beam loading and Lorentz detuning. A slow feedforward is used to cure the Lorentz detuning whereas a fast feedback through a signal oscillator and cavity pre-detuning technique are applied to eliminate the beam loading effect. An analysis performed with a Simulink model shows that a combination of feedforward, feedback and cavity pre-detuning result in a substantially shorter stabilization time of the field voltage and phase on a required level as compared to a control method using only the feedforward and feedback. The latter allows one to obtain smaller magnitude but longer duration of deviations of the instantaneous voltage and phase from the required nominal values. As a result, a series of cavities only with feedforward and feedback needs an extra control technique to mitigate a cumulative systematic error rising in each cavity. In addition, a technique of adiabatic turning off of the RF power in order to prevent a high reflected power in the case of a sudden beam loss is studied.  
 
FR1A05 SARAF Phase II P/D 40 MeV Linac Design Studies 1064
 
  • P.N. Ostroumov, Z.A. Conway, M.P. Kelly, A. Kolomiets, S.V. Kutsaev, B. Mustapha
    ANL, Argonne, USA
  • J. Rodnizki
    Soreq NRC, Yavne, Israel
 
  Funding: This work was supported by the ANL WFO No. 85Y47
The Soreq NRC initiated the establishment of SARAF – Soreq Applied Research Accelerator Facility. SARAF will be a multi-user facility for basic research, e.g., nuclear astrophysics, radioactive beams, medical and biological research; neutron based non-destructive testing (using a thermal neutron camera and a neutron diffractometer) and radio-pharmaceuticals research, development and production. The SARAF continuous wave (CW) accelerator is planned to produce variable energy (5-40 MeV) proton and deuteron beam currents (0.04-5 mA). Phase I of SARAF (ion source, radio-frequency quadrupole (RFQ), and one cryomodule housing 6 half-wave resonators (HWR) was installed and being operated at Soreq NRC delivering CW 1mA 3.5 MeV proton beams and low-duty cycle (0.0001) 0.3 mA 4.7 MeV deuteron beams. SARAF is designed to enable hands-on maintenance, which implies very low beam losses for the entire accelerator. The physics design of two options is explored to subsequently develop a conceptual design for selected option for extending the linac to its planned beam parameters (SARAF Phase-II: 40 MeV, 5 mA protons and deuterons).
 
slides icon Slides FR1A05 [3.459 MB]